Surface drain



Nov. 30, 1954 M. A SISK SURFACE DRAIN Origi'nal Filed Feb. 25, 19.46

w A a 5 4 9 aw k United States Patent F SURFACE DRAIN Martin A. Sisk, Pittsburgh, Pa.

Original application February 23, 1946, Serial No. 649,537, now Patent No. 2,607,434, dated August 19,

1952. Divided and this application July 20, 1950, Se-

rial No. 174,936

3 Claims. (Cl. 182-31) My invention relates to surface drains for use in the floors of shower baths, roadways, decks of ships, floors and roofs of buildings, and the like, to provide debris-excluding protection at the inlets of drain openings or pipes. The structure of the invention will also find utility as a guard for pipes and openings of any sort in which liquid is received, and in the operation of which it is desirable to exclude solids of a size that might clog the opening, or the pipe leading therefrom.

In general, an outlet or floor drain of the type in mind consists in a cup-shaped body that is embedded in the floor structure whose surface is to be drained, and the inlet of the body is covered by a removable grate Whose upper face lies flush with such surface. The body of the drain forms a belled terminus at the end of a drain pipe laid beneath or Within the floor structure.

a perforate plate of metal, rests at its periphery in a rabbetted seat formed in the rim of the cup-shaped body of the drain, and the greater part of the water entering the drain does so through holes or openings in the In the usual prior structures the grate, consisting in structure having a peripheral slot between the drain body rim and the edge or rim of the grate. This slot is effective substantially continuously throughout the periphery of the drain body inlet, and the internal surfaces of the drain body extend from this slot downwardly to the drain outlet, or to the inlet of the drain pipe on which the drain is mounted, afiording a clear unrestricted downsweep for the flow of the draining water. No ledges, channels, or crevices are present in the structure, on which or in which debris may accumulate.

In those cases where the drainage fluid includes a relatively large quantity of debris, it has been customary to provide a strainer within the drain body beneath the grate. This strainer is a cup-shaped receptacle having perforate walls. and in the prior drain structures of this sort substantially all of the water entering the drain goes through the strainer which catches and retains such particles of debris that might otherwise clog the drain, or the trap in the drain pipe leading therefrom. This type of drain is known as a non-clog drain.

My present invention consists in a strainer type drain structure embodying the features referred to in the above context.

The application for this patent comprises a division of my application Serial No. 649,537, filed February 23, 1946 (issued as Patent No. 2,607,434, August 19, 1952). Notice. is also given of my copending applications Serial No. 174,935, filed July 20, 1950, and Serial No. 356,748, filed May 22, 1953.

The invention will be understood upon reference to the accompanying drawings, in which:

Fig. 1 is a view in plan of a non-clog drain emb dying the invention; l Fig. 2 is a view of said drain in vertical section;

2,695,678 Patented Nov. 30, 1954 Fig. 3 is a fragmentary sectional view, showing a detail of construction on the plane IIIIII of Fig. 2; and

Fig. 4 is a fragmentary sectional view of a modified strainer element which may be used in the drain of this invention.

Referring to Figs. 1 and 2 of the drawings the drain body 2 will be seen to comprise an integral casting, a casting of iron, ordinarily, having a generally cylindrical side wall terminating in a rim 2b that defines the inlet of the drain. The rim is offset outwardly adjacent to the top of the side wall, to form a downwardly inclined seat 20 which extends in uninterrupted continuity around the periphery of said side wall. The inlet of the drain body is covered by grate 50, the grate being disposed Within the inlet. Medially of its vertical extent the side wall is tapered inwardly, as at 2d, to a threaded opening 2e which forms the outlet of the drain, and provides for the attachment of the drain body to the threaded end of a drain pipe on the inlet side of the conventional trap (not shown). Extending laterally from the drain body is a circumferential flange 2 At this point, it may be mentioned that in lieu of the threaded outlet 22 the drain body may be shaped below the tapered wall portion 2d to form a hell-and-spigot joint with the terminus of the drain pipe, and, alternately, the drain outlet may open laterally instead of downwardly. These are details well-known to the art.

The drain structure includes a cup-shaped strainer 49, comprising a metal casting having rectangular openings 49a in its side wall, and a rim equipped with lugs 49b and 490 which rest upon the seat 20 in the drain body and support the strainer. The grate 50 comprises a body including slots 500, said body having a peripheral rim or flange 50b which seats on, and is supported by, the rim of the strainer.

The lugs 49b and 49c extending radially from the rim of the strainer body are designed to lie below the rim 2b of the drain body an interval exactly equal to the thickness of the flange 50b of the grate, whereby the top of the grate in the assembly lies flush with the rim 2b of the drain body. The diametrically opposite lugs 49b of the strainer are of the recessed structure shown in Fig. 3, affording advantages of the sort described in my copending application Serial No. 649,537, and through a hole in each lug 49b and the superposed flange 50b of the grate a screw 8 is passed and secured in a threaded bushing 9 in a boss 2h integrally formed on the drain body side wall. Thus, both the grate and the strainer are removably secured in assembly with the drain body.

In the drain structure described it will be perceived that the internal surface of the drain body side wall extends downward from the rim 2b in a series of smooth surface areas; that is, the surface above the downwardly sloped seat 20, the surface of such seat, the surface of the side wall below the seat and the surface of the inclined. wall portion 2a. This vertical succession of internal side wall surfaces provides a continuous downsweep that is entirely unobstructed, having no recesses nor ledges, it being noted that the two bosses 2h extend with smooth surfaces all of the distance from' the strainer lugs 49b to the inclined wall portion 2d. Hence, there are no restrictions or obstructions within the drain body upon which solids included in the drainage water can accumulate. Cooperating with this unrestricted downsweep form of the internal surfaces of the drain body is the provision of a flushing slot 51 which comprises a plurality or series of unobstructed and relatively long auxiliary slots disposed outwardly from the rims of the strainer and of the grate: the succession of auxiliary slots provides in practical effect a single slot that extends Without interruption around the entire periphery of the inlet of the drain body, since the widely spaced, narrow lugs 49b and 490 do notinterfere with the operation or functioning of the drain in the manner described below. As shown, the slot 51 is formed by and between the peripheral edges of the strainer and grate bodies and the adjacent edge of the rim 2b of the inlet. The outer edge of this slot 51 is coincident or flush with the internal surface of the drain body, whereby water entering the drain body fiows directly downward upon and around the entire periphery of the drain body, at the floor or drainage area level, and subjects all of the mternal surface areas of the drain body, all of the way downward from the rim of such body, to an eflective downsweep of water. All of the internal surface areas of the drain body are downwardly extending, and under the flushing flow of water it is impossible for the drain to become fouled by accumulations of dirt, grease or other sediment.

The peripheral slot 51 and system of medial slots 500 in the grate provide an effective inlet area that is substantially fifty per cent greater than usual, whereby greater than usual quantities of water can be handled in a drain of given size.

Another point may be mentioned. Since the strainer and grate are supported by lugs located outward from their rims, the tendency is negatived for the grate and strainer to tilt when pressure or load is applied to the rim of the grate. indeed, the grate and strainer tend to seat tighter and to be more resistant to tilting when load is applied, as it may be within the limits of the points of support.

It will be noted that the lugs 49b and 49c are of relatively small circumferential extent with respect to the intervening peripheral slots that form the peripheral or auxiliary slot 51. The lugs 49b and 490 engage the drain body over relatively small areas, and the internal surface of the drain body between the narrow supporting lugs is vertically or sharply inclined downwardly all of the way from the top of the rim to the outlet. The outwardly extending lugs not only support the strainer and grate on the drain body, but space the grate and strainer with their rims away from the wall of the drain body.

The rim of the strainer is inset below the edge 50a of the grate flange 50b, and thereby provides no obstruction of the slot 51, and presents no ledges upon which debris, grease or dirt may collect. The peripheral slot 51 is made narrower than the medial slots 500 of the grate, and the narrower form of the peripheral slot is intentionally provided to insure that most of the water and all of the sizable solids will drain through the center of the grate, with the effect that the sizable solids will not escape through the peripheral slot 51 but will be caught in the strainer. However, the slot 51 is of adequate width to permit an effective scavenging flush of water to sweep the entire internal surfaces of the drain body, without danger of large particles of debris entering the slot and by-passing the strainer.

An important characteristic of the strainer 49 is that it may be cast integrally in a green sand mold without the aid of cores. The parting line or plane of the mold is coincident with the plane of the upper edges of the rim and lugs of the strainer. The body of sand in the cope or male member of the mold is shaped to the form of the interior of the strainer body, while the sand in the drag or female member of the mold is shaped into a cavity conforming to the outside surfaces of the strainer body and of the bodies of the lugs 49!) and 490. When the two parts of the mold are assembled, a matrix is provided for shaping cast molten metal to the form of the strainer body. To this extent the practice is conventional, but in refinement of such conventional practice the strainer perforations are completely formed in the molding operation. Such forming of the perforations in the strainer side Wall is accomplished by providing on the sand wall of the cavity in the female mold member protuberances which are of the exact shape and arrangement of the perforations to be formed in the strainer side wall. The inner edges or faces of these molded-sand protuberances in the female mold member are adapted in the assembled mold to lie flush against the surface of the molded sand of the male mold member, whereby in the casting operation the molten metal is blanked out within the regions in the mold matrix occupied by the protuberances, thus forming the perforations in the strainer body. The accomplishment of this result in a green sand mold is of great practical value, and the feature by virtue of which the accomplishment becomes possible consists in circumferentially insetting the side wall of the strainer body, as indicated at 49d. The extent or degree of this insetting of said side wall is such that the outer surface 492 of the lower side wall portion may be a continuation of or inset from the same conical surface that forms the internal surface 49 of the upper side wall portion, for in this way the pattern used in forming the cavity in the green sand of the female mold member may be freely withdrawn from the molded sand without disrupting the protuberances integrally molded in the sand and outstanding from the surface of the mold cavity. This will be understood upon considering the outer surfaces of the strainer body, as shown in Fig. 2, to be the surfaces of the pattern upon which the sand is molded. It will be understood that the side-wall-forming portions of the pattern above and below the circumferentially extending offset (49d) are both made coniform, or drafted sufficiently, to permit the free withdrawal of the pattern from the molded sand, and since the lower side-wall-forming portion is inset (see 49d) from the upper side-wall-forming portion of the pattern there is nothing to interfere with the clean removal of the pattern from the sand, it being noted that the vertical face of each of the recesses in the body of the pattern which mold the upper row of perforationforming protuberances on the surface of the mold cavity is continued downwardly in a surface portion (s'ee 49h) that forms the outer surface of the strainer side wall at the offset 49d, and adjacent to one end (the bottom) of each perforation 49a. The vertical face of each of the recesses in the pattern body which mold the lower row of perforation-forming protuberances in the mold is continued downwardly in a surface portion (see 49i) that is aligned with the inner surface of the strainer side Wall at the olfset 49d. In consequence of these structural details the pattern, which forms the laterally extending perforationforming protuberances in the molded green sand, is adapted to be withdrawn from the sand without harm to the mold.

It will be seen from the foregoing that the pattern which is used to mold the cavity in the female mold member is adapted to form on the wall of such cavity the protuberances which form the perforations in the side wall of the strainer 49. Alternatively, the perforation-forming protuberancejs may be provided on the side surface of the male mold member, and this alternative practice is made feasible by forming the strainer body in such manner that the surface portions 49h and 49i are provided on the internal rather than on the external surface of the strainer body. Fig. 4 illustrates a strainer body 54 modified in the particulars required, the surface portions 54h and 54i being the counterparts of the surface portions 4911 and 491 of the strainer structure of Fig. 2. Since in molding the sand for the strainer body of Fig. 4, the pattern which forms the perforation-forming protuberances is a recessed pattern in which the sand of the male member is molded and then withdrawn, the strainer 54 is termed an inside draw structure, and for corresponding reasons the strainer 49 is termed an outside draw structure.

Needless to say there may be a wide variation in the form and arrangement of the perforations provided in the strainer bodies of the invention. And manifestly the nonclog structures of Figs. 1 to 4 can be incorporated in square, rectangular, or octagonal drain structures, described in my said copending applications.

Certain modifications and refinements will occur to those skilled in the art Without departing from the spirit of the invention defined in the appended claims.

I claim:

1. In a non-clog surface drain comprising a drainbody provided with an inlet having a rim adapted to lie flush with the surface to be drained, said drain body having a peripheral side wall extending downwardly from said rim to an outlet, a strainer of cup-like form supported in said drain body, and a grate supported in position across said inlet of the drain body; the invention herein described wherein the side wall of the drain body is formed with an internal surface that extends downwardly from the inner edge of said rim to said outlet, providing a continuous downsweep that is smooth and substantially unrestricted throughout the peripheral and vertical extents of said side wall, said grate comprising a disk-like body having within its peripheral edge a system of perforations for the drainage of liquid into said drain body, a downwardly sloping side wall portion on said drain body within and below said rim, said strainer having a peripheral edge with a plurality of radiating circumferentially spaced lugs extending outwardly therefrom, saidlugs being supported on said downwardly sloping side wall portion of the drain body, with said peripheral edge of the strainer positioned below said rim of the drain body inlet and below the surface to be drained, and with said edge of the strainer spaced at an interval inwardly from said rim of the drain body inlet, said grate having a rim resting upon the rim of the strainer, with the top surface of the rim of the grate flush with the top surface of the rim of the drain body inlet, the rim of the grate being also spaced inwardly from the rim of the drain body, said rims of the strainer and of the grate forming with the rim of the drain body inlet a drainage slot that extends in substantial continuity throughout the periphery of said inlet, whereby in service the entire internal surface of the drain body is flushed by an unrestricted downsweeping flow of drainage liquid.

2. In a non-clog surface drain comprising a drain body provided with an inlet and having a peripheral side wall extending downwardly from the rim of said inlet to a circular outlet, said side wall comprising a substantially vertical peripheral wall portion extending downwardly from said rim and fairing smoothly with an annular peripheral wall portion that slopes downwardly to said outlet, forming internal surfaces in the drain body that provide a substantially continuous downsweep that is substantially unrestricted throughout the peripheral extent of the side wall, a strainer of cup-like form supported in said drain body, and a grate supported in position across said inlet of the drain body; the invention herein described comprising a peripherally extending downwardly sloping seat on the internal face of said drain body side Wall, radially extending relatively narrow lugs on the cup-like strainer engaging said seat to support said strainer in the drain body, with the rim of the strainer spaced at an interval inwardly of said rim of the drain body inlet, said grate comprising a disk-like body having within its peripheral edge a system of perforations for the drainage of liquid therethrough, said grate being seated upon the strainer body, with the top surface of the peripheral edge of the grate substantially flush with the top surface of the rim of the drain body inlet, the peripheral edge of the grate being also spaced inwardly from said rim of the drain body inlet, whereby a drainage slot is provided between the rim of the drain body inlet and the bodies of said strainer and grate, said drainage slot extending in substantial continuity throughout the periphery of the drain body inlet to provide in service an unrestricted downsweeping flow of drainage liquid that thoroughly flushes the internal surfaces of the drain body.

3. In a non-clog surface drain comprising a drain body provided with an inlet and having a peripheral side wall extending downwardly from the rim of said inlet to a circular outlet, said side wall comprising a substantially vertical peripheral wall pc'tion extending downwardly from said rim and fairing smoothly with an annular peripheral wall portion that slopes downwardly to said outlet, forming internal surfaces in the drain body that provide a substantially continuous downsweep that is substantially unrestricted throughout the peripheral extent of the side wall, a strainer of cup-like form supported in said drain body, and a grate supported in position across said inlet of the drain body; the invention herein described comprising seating means on said drain body within and below said rim for the support of said strainer while providing for the said substantially continuous unrestricted downsweep, portions of relatively narrow extent peripherally of the rim of said cup-like strainer engaging said seating means to support the strainer in the drain body, with the rim of the strainer spaced at an interval inwardly from said rim of the drain body inlet, said grate comprising a disk-like body having within its peripheral edge a system of slots for the drainage of liquid therethrough, said grate being seated upon the strainer body, with the top surface of the peripheral edge of the grate substantially flush with the top surface of the rim of the drain body inlet, the peripheral edge of the grate being also spaced inwardly from said rim of the drain body inlet, whereby a peripheral drainage slot is provided between the rim of the drain body inlet and the bodies of the strainer and grate, said peripheral slot being narrower than the slots in the grate body, with the effect that most of the drainage liquid and substantially all of the sizable solids will drain through the grate into the strainer that will catch and retain such solids, while permitting a lesser but effective scavenging quantity of water to fiow through said peripheral slot and flush the internal surfaces of the drain body.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,434,254 Sanders Oct. 31, 1922 1,972,513 Drehmann Sept. 4, 1934 2,101,978 Boosey Dec. 14, 1937 2,142,343 Boosey Jan. 3, 1939 2,299,705 Svirsky Oct. 20, 1942 2,400,070 Boosey May 14, 1946 

